With Brazilian legend Gustavo Kuerten in attendance, the World No. 8 claimed his eighth ATP World Tour crown, second at the 500 level and third on the Golden Swing, having previously triumphed in Buenos Aires and Acapulco in 2016. He fired 25 winners, including 14 on his forehand wing and seven aces to prevail over Carreno Busta. Thiem also converted four of eight break chances in extending his FedEx ATP Head2Head edge to 5-1.

"I am feeling really great," said Thiem. "This is the best feeling you can have, winning a title. It's all you practise for. I played five very good matches, especially in the semis and final against amazing players.

"I did same thing last year, going from clay to hard in Acapulco and I did well. It's a slower hard court with a high bounce, so it's what I like. It's not easy with the travel and time difference, but the confidence is high and I'm feeling great."

With rain drops falling over Quadra Guga Kuerten, Carreno Busta took the early lead with a break for 3-2 as he looked to extend his strong run of form in Rio. A day removed from a thrilling comeback over teenager Casper Ruud to reach the final, battling back from a set and a break down and fighting off a match point, he was riding a wave of momentum.

But Thiem entered the final without dropping a set on the Brazilian clay, making a seemless transition from the indoor hard courts of Rotterdam. The trend would continue, as the second seed broke right back for 3-3 and eventually converted his third set point, breaking again for 7-5.

The lead would trade hands midway through the second set, as Thiem edged ahead with a drop shot winner for 4-2 and Carreno Busta drew level with a sublime drop shot of his own in the next game. Thiem was tested, but he would not be denied the title, breaking for the match as the Spaniard sent a forehand long.

Thiem takes $314,880 in prize money and 500 Emirates ATP Rankings points, extending his win streak over Carreno Busta to four straight at the tour-level. They met twice in 2016, with the Austrian winning in three sets in Buenos Aires and in four at the US Open.

Carreno Busta, meanwhile, was bidding for his third ATP World Tour title in his fifth final. He prevailed in the doubles final on Saturday with Pablo Cuevas, dethroning defending champions Juan Sebastian Cabal and Robert Farah.

"Obviously, I'm very happy after a week like this," said Carreno Busta. "Winning the title in doubles and reaching the final in singles is great. Dominic is a fantastic player and is going to win many more titles in the coming years. I hope I can play more finals against him.

"Physically I felt great all week. I'm a little tired, but that's normal after these couple of days. I have a few days to rest and now I'm looking forward to Sao Paulo."

The 25 year old, who was looking to join Rafael Nadal (2014) and David Ferrer (2015) as Spanish champions in Rio de Janeiro, earns 300 Emirates ATP Rankings points and $154,370 in prize money. He is projected to rise one spot to a career-high World No. 23 on Monday.